Binary Difference Operations for Navigational Bit Streams

ABSTRACT

A computing device may identify a series of bits representative of a first binary large object (BLOB) for navigation data including road segments and road attributes. The computing device duplicates each bit of the series of bits a predetermined number of times to form a first bit string. The first bit string is larger than the series of bits by a factor of the predetermined number. The computing device performs a binary difference of the first bit string to a second bit string representative of a second BLOB. A result of the binary difference is stored in a navigation patch file.

FIELD

The following disclosure relates to map updates, and more particularlyto map updates of a geographic database based on binary differenceoperations.

BACKGROUND

Map databases are used in computer-based systems that provide usefulfeatures to users. For example, the identification of routes todestinations or points of interests. A navigation system determines theoptimum route to be taken by the end user to travel from the origin tothe destination location from map data stored in a geographic (or map)database. Map databases are also used in advanced driver assistancesystems, such as curve warning systems, adaptive cruise control systemsand headlight aiming systems. Map databases are also used in systemsthat improve vehicle fuel economy, such as systems that optimizetransmission gear selection taking into account upcoming slope and speedchanges.

As new roads are built, other roads are closed, or locations of businessare changed, the geographic database is updated. One way to update mapdata is to replace the entire existing map database with a new versionof the geographic database containing new, updated map data. However, areplacement of the entire map database is a relatively expensive andtime consuming process and may be unnecessary considering that much ofthe map data may not be changed from the old version to the new version.Further, wholesale map updates in mobile devices introduce challengesbecause bandwidth is often limited and map updates are often bulky andrequire high bandwidth.

SUMMARY

In one embodiment, a computing device identifies a series of bitsrepresentative of a first binary large object (BLOB) for navigation dataincluding road segments and road attributes. Each bit of the series ofbits is duplicated a predetermined number of times to form a first bitstring. The first bit string is larger than the series of bits by afactor of the predetermined number. The computing device performs abinary difference of the first bit string to a second bit stringrepresentative of a second BLOB. A result of the binary difference isstored in a navigation patch file.

In one embodiment, an apparatus determines a first series of bitsrepresents an object of a BLOB for existing navigation data include roadsegments and road attributes and identifies a second series of bits fora new version of the object of the BLOB. The first series of bits isinflated by a predetermined number of times to form a first bit string.The first bit string is larger than the first series of bits by a factorof the predetermined number. The second series of bits is inflated bythe predetermined number of times to form a second bit string. Thesecond bit string is larger than the second series of bits by a factorof the predetermined number. The apparatus calculates a binarydifference of the second bit string and the first bit string and storeslocation values for a result of the binary difference in a navigationpatch file.

In one embodiment, a computing device receives a navigation patch fileand determines a first series of bits for an object of a BLOB for acurrent version of navigation data that corresponds to the navigationpatch file. The first series of bits is duplicated by a predeterminednumber of times to form a bit string, and the bit string is updatedaccording to the navigation patch file. The computing device reduces theupdated bit string according to the predetermined number of times toform a second series of bits and inserts the second series of bits inplace of the first series of bits in the object of the BLOB.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention are described herein withreference to the following drawings.

FIG. 3 illustrates an example map tile described as a tree datastructure.

FIG. 2 illustrates an example map developer system.

FIG. 3 illustrates an example conversion from a bit stream to a bitstring.

FIG. 4 illustrates an example binary difference for bit strings.

FIG. 5 illustrates an example update script.

FIG. 6 illustrates an example block diagram for generating a patchprogram.

FIG. 7 illustrates an example server of the map developer system.

FIG. 8 illustrates an example flowchart for the server of FIG. 7.

FIG. 9 illustrates an example mobile device in communication with themap developer system.

FIG. 10 illustrates an example flowchart for the mobile device of FIG.9.

DETAILED DESCRIPTION

Significant efforts have been directed toward update techniques fornavigation databases on embedded devices, including mobile phones orhead units in vehicles. As the amount of navigation related content andfeatures on these devices increases, so does the size of the database.As a consequence, the update scripts for keeping the databases up todate with changes in locations, points of interests, and road networkhave been increasing in size. A lot of data is organized in BLOBs(binary large objects) such as routing or basic map display data. Thecontent of these BLOBs may include “metadata” and “payload” data whichis often organized in lists. A navigation file (e.g., SQLite file) mayinclude dozens to thousands of BLOBs in tables.

FIG. 1 illustrates a BLOB structure 10 for the main routing function ofa navigation database, which may be referred to as the routing tile. Therouting tile includes metadata and payload. As illustrated, the metadataincludes the routing tile header and the payload includes various liststructures such as road segment list 11, road attribute list 13, androad intersection list 15.

The lists may be various sizes. The basic map display may also includemany area, line, and point lists. The road attributes 13 may includeproperties such as functional classification, speed limit, slope, numberof lanes, or other attributes. The lists may include road segmentidentifiers and an array of attributes for road segment. Additional,different, or fewer lists may be included in the BLOB structure 10. Inthe navigation database, some of the data may be byte aligned or have astandard number of bits. That is, the number of bits is divisible by apower of 2 that is 8 or greater such that an integer number of bytes areused (8 bits make up 1 byte). Other data may be not byte aligned (bytemisaligned) and have a nonstandard number of bits indivisible (notdivisible) by 8. One example is an attribute for the type of link thatincludes only 6 bits, resulting in link objects that occupy n bytes andm bits, with m being between 0 and 7. For example, when four 6-bitobjects are used, the 24 total bits span 3 bytes. The type of linkattribute may provide a coarse direction for the direction of a roadsegment. The direction may be described a 6 bit number from 0 to 64 thatare counted clockwise with sector 9 indicative of a North direction.

Another example of binary encoding may be a basic map display. The coreof the basic may display may include 6 bits followed by a list ofpolygon points. Each of the polygon points describes a location wherefor each point encoded with a certain number of bits, which may beunequal to 8 or 16 bits. The anchor point may be listed followed by avalue describing the number of bits excluding the sign bit. Next, anedge indicator determines whether the edge for the vertex is a pseudoedge that may have resulted from clipping or triangulation. Finally, theremaining vertices are listed.

Replacing the entire navigation database during an update requiressignificant bandwidth and time. Instead, an update script may be used sothat only the changes are sent from the map developer to the embeddeddevice. One technique for identifying the changes is a binarydifference. The binary different calculates the difference between twobit strings. The binary difference compares the first bit in one stringto the first bit of the other string and so forth.

This may be illustrated using two example bit strings and thehexadecimal representation. Consider bit string A below having 8-bitbytes indicated by alternating underline and not under line and 6-bitobjects indicated by alternating bold and not bold.

101100110000111000111000000110010010010000111001010001111110001100000100001000010000010000100111

Bit string A may be represented in hexadecimal by

B30E3819243947E304210427

A new 6-bit object “110011” is inserted at position 2 of the list(becoming the second 6-bit object in the bit string), to form bit stringB below:

101100110011110000111000111000000110010010010000111001010001111110001100000100001000010000010000100111

The hexadecimal representation of the bit string B would be would be

B33C38E06490E51F8C1084109C.

The two hexadecimal representations differ greatly. Rather than a changeto 1 byte and shifting values by one byte, all bytes have been altered.Reproduced for comparison are the hexadecimal representations of stringsA and B.

-   -   String A: B30E3819243947E304210427 (before inserting)    -   String B: B33C38E06490E51F8C1084109C (after inserting)

The hexadecimal representations are quite different. Because the objectsare 6 bits in length, and bytes are 8 bits in length, objects overlapbytes. Thus, most or every value after the insertion has changed.Performing a binary difference on strings A and B results in a largedifference. Describing an update to a navigation database using binarydifference in the example would be high cost. For a navigationaldatabase including BLOBs, a straightforward binary difference of the oldand new BLOB may lead to a rather large update package, even in theinstance that only one element is inserted or deleted.

The following embodiments describe examples for an incremental updatefor a navigational database includes BLOBs with a bit to byte conversionbefore a binary difference operation is performed between an old versionof the database and a new version of the database. The bit to byteconversion modifies each individual bit to a series of bits having thesame value. Each series of bits may have a 1-byte size. In other words,the bit 0 is converted to 00000000, and the bit 1 is converted to11111111. The inflated data may be eight times larger than the originaldata. After compression is applied, the result of the binary differencemay be significantly less than eight times larger but still greater thanthe actual difference between versions of the database. The result ofthe binary difference of the inflated data is significantly smaller thanthe entire database or the binary difference in the example above.

FIG. 2 illustrates an example map developer system 120 for updatingnavigation databases. The system 120 includes a developer system 121,one or more mobile devices 122 (navigation devices), a workstation 128,and a network 127. Additional, different, or fewer components may beprovided.

For example, many mobile devices 122 and/or workstations 128 connectwith the network 127. The developer system 121 includes a server 125 andone or more databases. The database 123 a-b may be a geographic databaseincluding road links or segments. As shown in FIG. 2, a master copy ofthe database 123 a may be stored at the developer system 121, and alocal copy of the database 123 b may be stored at the mobile device 122.In one example, the local copy of the database 123 b is a full copy ofthe geographic database, and in another example, the local copy of thedatabase 123 b may be a cached or partial portion of the geographicdatabase. The cached portion may be defined based on a geographiclocation of the mobile device 122 or a user selection made at the mobiledevice 122.

The server 125 may send map updates to the mobile device 122. The server125 may update a particular tile of the geographic database 123. Theserver 125 may send updates to the master copy of the database 123 aand/or send updates to the local copy of the database 123 b. The server125 may generate an update script for the navigation data. The server125 may identify a series of bits representative of a first binary largeobject (BLOB) for navigation data include road segments and roadattributes. The series of bits may be a portion of the BLOB or theentire BLOB. The server 125 may identify the series of bits in responseto a byte misalignment in the BLOB.

The server 125 may inflate the series of bits in order to convert eachsingle bit in the series of bits to a byte sized string of bits. Inother words, the server 125 duplicates each bit of the series of bits apredetermined number of times to form a first bit string. The first bitstring is larger than the series of bits by a factor of thepredetermined number. The predetermined number may be 8 so that each bitvalue becomes byte of all the same bit value. The bit value 1 becomes11111111, and the bit value 0 becomes 00000000. The duplication of theseries of bits may be in response to the identification of thenonstandard number of bits.

The server 125 is configured to perform a binary difference operation.The binary difference operation may be byte subtraction. The binarydifference operation may compare data on the byte level. For example,when current navigation data is compared to new navigation data arecompared, the first byte of the current navigation data is compared tothe first byte of the new navigation data, the second byte of thecurrent navigation data is compared to the second byte of the newnavigation data, and so on. The result of the binary differenceoperation may include the byte locations of the differences in the dataand the edit operation for that location. Example edit operationsinclude add data, delete data, or modify data. However, because the datainclude bytes that have all of the same bits (i.e., the onlypossibilities may be 00000000 and 11111111), there is only one choicefor a chance in the data. In other words, since only one type of changeis possible, the result of the binary difference operation may besimplified to only include the byte locations of the changes.

The server 125 may also convert the second BLOB for comparison with thefirst blob. Thus, the server may identify a second series of bitsrepresentative of the second BLOB for navigation data include roadsegments and road attributes and duplicate each bit of the second seriesof bits the predetermined number of times to form the second bit string,wherein the second bit string is larger than the second series of bitsby a factor of the predetermined number.

The server 125 may store the results of the binary difference in anavigation patch file. The navigation patch file may be stored in thegeographic database 123 a. One example navigation patch file includesbyte locations only. For example, [4, 50, 123] indicates that three bitsare changed at the 4^(th), 50^(th), and 123^(rd) byte locations. Theexample navigation patch file may be mixed with complex data that isadded at other portions of the BLOB.

The database 123 may store or maintain geographic data such as, forexample, road segment or link data records and node data records. Thelink data records are links or segments representing the roads, streets,or paths. The node data records are end points (e.g., intersections)corresponding to the respective links or segments of the road segmentdata records. The road link data records and the node data records mayrepresent, for example, road networks used by vehicles, cars, and/orother entities.

The mobile device 122 may be a personal navigation device (“PND”), aportable navigation device smart phone, a mobile phone, a personaldigital assistant (“PDA”), a tablet computer, a notebook computer,and/or any other known or later developed mobile device or personalcomputer. Non-limiting embodiments of navigation devices may alsoinclude relational database service devices, mobile phone devices, orcar navigation devices.

The developer system 121, the workstation 128, and the mobile device 122are coupled with the network 127. The phrase “coupled with” is definedto mean directly connected to or indirectly connected through one ormore intermediate components. Such intermediate components may includehardware and/or software-based components.

The computing resources may be divided between the server 125 and themobile device 122. In some embodiments, the server 125 performs amajority of the processing for calculating the vehicle confidence valueand the comparison with the confidence threshold. In other embodiments,the mobile device 122 or the workstation 128 performs a majority of theprocessing. In addition, the processing is divided substantially evenlybetween the server 125 and the mobile device 122 or workstation 128.

FIG. 3 illustrates an example conversion from a bit stream 21 to a bitstring 23. In one example, the bit stream may be any number of bits. Inanother example, the bit stream has a nonstandard number of bits (e.g.,1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, or 8*n+x, wherein n isan integer and x is any of the preceding values). The bit stream mayrepresent data in a navigation tile such as road attributes. The bitstream may be converted to the bit string 23. Each bit is convert to arepeating sequences of the same bit.

FIG. 4 illustrates an example binary difference for bit strings. The bitstream 21 and bit string 23 may represent a new version of an object ofnavigation data having a number of bits that is not a multiple of 8. Thebit stream 27 and bit string 25 may represent an old or previous versionof the same object of navigation data. The binary difference operationmay identify differences in the byte length data in the bit string 23and the bit string 25. The arrow 29 illustrates the only differencebetween the two versions of the navigation data in the exampleillustrated. The difference is one bit between the bit stream 21 and bitstream 27. The difference is one entire byte between the bit string 23and the bit string 25.

FIG. 5 illustrates an example update script 30. The data for the mapupdate 30 includes portions 31 through 39. Rather than storing thecomplete inflated version of the binary information in the overallupdate script, simple binary difference data may be used when the binaryobjects are byte aligned. Simple binary difference data may be based onthe hexadecimal representations for those portions. Portions that arehatched (e.g., portions 31, 33, and 35) represent simple binarydifference data.

The other portions (e.g., portions 32, 34, 36, and 37) include theupdate for portions that are not byte aligned. For the portions that arenot byte aligned, the bit string is expanded to one byte per bit beforethe binary difference operation is performed. In other words, thecomplex binary difference data for portions 32, 34, 36, and 37 may becomputed based on first inflating the bit stream to repeating series ofbits for each value and subsequently performing the binary differenceoperation on the repeating series of bits.

As described above, all of the data of a BLOB or file may be inflatedbefore performing a binary difference operation to create an updatepatch. When portions of the data are already byte aligned, thoseportions will have some identical strings in the inflated data. Theidentical portions will have an empty or zero binary difference.Therefore, these algorithms automatically reverse the inefficiencies ofinflating the bits for portions that do not need to be inflated.

In an alternative embodiment or example, the server 125 may distinguishdifferent portions of the BLOB or file. FIG. 6 illustrates an exampleblock diagram for generating a patch program. The block diagram beginswith binary data 41. The server 41 is configured to classify the binarydata 41. In one example, the binary data 41 is divided into objects madeup bits. Each object may describe an aspect of a navigational data. Someobjects such as the name of a road segment, which is made ofalphanumeric characters, may include a whole number of bytes. Someobjects, such as an attribute list, may be described using less than awhole number of bytes.

The server 41 may apply a modulus function to objects to determinewhether the objects should be classified as a byte aligned portion 43 ora byte misaligned portion 45. For example X mod 8, where X is the numberof bits in the object returns a value equal to the reminder after X isdivided by 8. When the value is 0, the object is byte aligned andclassified in the byte aligned portion 43. When the value is any valueexcept 0, the object is byte misaligned and classified in the bytemisaligned portion 45.

The objects classified in the byte aligned portion 43 proceed directlyto the binary difference operation 46. The binary difference operation46 may first convert the object to a hexadecimal representation. Theneach hexadecimal value (e.g., pair of alphanumeric values) for theobjects are compared to a prior version of the object. The difference isstored in the update script 49 or navigation data patch program.

The objects classified in the byte misaligned portion 45 proceed to abit to byte conversion 47. The bit to byte conversion 47 converts eachsingle bit to a series of bits having a byte length. The data size ofthe objects in the byte misaligned portion 45 may be inflated by afactor of 8. After the bit to byte conversion 47, the series of bitsproceed to binary difference operation 48. Conceptually, the binarydifference operation 46 and the binary difference operation 48 may bemerged. The result of the binary difference operation 48 may includeinstance labels, or byte locations, wherein the bit streams describe thebyte misaligned objects are compared to a prior version of the object.The difference is stored in the update script 49 or navigation datapatch program, for example, according to the technique described abovewith respect to FIG. 5.

The navigation data patch program or update file may be applied toanother version of the BLOB (third BLOB) of a navigation database. Theto-be-updated navigation database may be a database maintained by theserver 125. The to-be-updated navigation database may be stored locallyat a mobile device 122. The to-be-updated navigation database may bestore at a third party customer. In some examples, the third party ofmobile device 122 requests updates. In some examples, the updates arebroadcasted or sent out according to a time schedule.

The application of the navigation data patch program or update file mayalso involve inflating the bits of the to-be-updated objects. Forexample, each bit of the third BLOB may be duplicated from the format ofthe navigation database by repeating the bits for the predeterminednumber of times to form a third bit string. The third bit string may bemodified based on the navigation patch file. Finally, the inflatedstream of bits is deflated to convert each byte of repeating bits backto a single bit of the third bit string to return to the format of thenavigation database. In another example, the navigation data patchprogram or update file includes bit locations of the two be changedbits, which may be applied directly to the stream of bits withoutinflating and subsequently deflating the stream of bits for the thirdBLOB.

Consider one example first version of a bit stream or BLOB:

101100110000111000111000000110010010010000111001010001111110001100000100001000010000010000100111,and a second version of the same bit stream or BLOB having a new portionunderlined:10110011001111000011100011100000011001001001000011100101000111111000011000001000010000010000100111.

Before the comparison, both bit streams are inflated. The first bitstream is inflated to “11111111 00000000 11111111 11111111 0000000000000000 11111111 11111111 00000000 00000000 00000000 00000000 1111111111111111 11111111 . . . ” The second bit stream is inflated to “1111111100000000 11111111 11111111 00000000 00000000 11111111 11111111 0000000000000000 11111111 11111111 11111111 . . . ” When the first bit streamand the second bit stream are identical, as in the first 10 bits, theinflated portions of the first bit stream and the second bit stream areidentical. The binary difference at these identical portions is 0 ornul. On the other portions of the bit stream, the binary differencedescribes the differences of the inflated portions.

In one example, the update script includes three instructions to createa new file: (1) keep bytes 1 to 10 of the old file in the same positionin the new file, (2) insert the extra bytes “111100” and add them to thenew file, and (3) appends bytes 11 to 86 from the old file after theinserted bytes.

FIG. 7 illustrates an example server 125. The server 125 includes aprocessor 300, a communication interface 305, and a memory 301. Theserver 125 may be coupled to a database 123 and a workstation 310. Theworkstation 310 may be used to enter data regarding the type of updatescript that will be used (e.g., binary difference versus bit to byteconversion). The database 123 may be a geographic database as discussedabove. Additional, different, or fewer components may be provided in theserver 125. FIG. 8 illustrates an example flowchart for the operation ofserver 125. Additional, different, or fewer acts may be provided. In actS101, the processor 300 determines a first series of bits represents anobject of a BLOB for existing navigation data include road segments androad attributes. For example, the processor 300 may calculate a modulusfunction based on the predetermined number for the BLOB. When a resultof the modulus function is nonzero, the object is labeled as a bytemisaligned object.

At act S103, the processor 300 identifies a second series of bits for anew version of the object of the BLOB. In one example, the processor 300identifies an object identifier from the existing version of thedatabase in S101 and accesses the corresponding object in the newversion of the database based on the object identifier. In anotherexample, the object in the new version of the database may be identifiedbased on comparing the data in the objects.

At act S105, the processor 300 duplicates or inflates the first seriesof bits by a set number of times to form a first bit string. Similarly,at act S107, the processor 300 duplicates or inflates the second seriesof bits by the set number of times to form a second bit string. Theresulting first and second bit stream are larger than the respectivefirst and second series of bits by a factor of the set number.

At act S109, the processor 300 calculates a binary difference of thesecond bit string and the first bit string. One algorithm forimplementing the binary difference may be bsdiff or bsdiff[z], where zis the base number. The result of the binary difference may includelocation values that indicate byte sequence numbers in which adifference was calculated between the second bit string and the firstbit string.

At act S111, the memory 204 stores location values for a result of thebinary difference in a navigation patch file. The navigation patch filemay be sent to the mobile device 122, or any navigation device, upon areceived request or according to a time schedule.

The geographic database may include road segments or links. Each roadsegment is associated with two nodes (e.g., one node represents thepoint at one end of the road segment and the other node represents thepoint at the other end of the road segment). The node at either end of aroad segment may correspond to a location at which the road meetsanother road, i.e., an intersection, or where the road dead-ends. Theroad segments may include sidewalks and crosswalks for travel bypedestrians.

Each of the road segments or links may be associated with variousattributes or features stored in lists that are not byte aligned. Theroad segment data record may include data that indicate a speed limit orspeed category (i.e., the maximum permitted vehicular speed of travel)on the represented road segment. The road segment data record may alsoinclude data that indicate a classification such as a rank of a roadsegment that may correspond to its functional class. The road segmentdata includes a segment ID by which the data record can be identified inthe geographic database 123. The road segment data, nodes, segment IDs,attributes, fields, and other data may be organized in data structuresdescribed above.

The road segment data may include data identifying what turnrestrictions exist at each of the nodes which correspond tointersections at the ends of the road portion represented by the roadsegment, the name or names by which the represented road segment isknown, the length of the road segment, the grade of the road segment,the street address ranges along the represented road segment, thepermitted direction of vehicular travel on the represented road segment,whether the represented road segment is part of a controlled access road(such as an expressway), a ramp to a controlled access road, a bridge, atunnel, a toll road, a ferry, and so on. The additional road segmentdata may be organized in data tree structures. Alternatively, the datatree structures may be included in a separate database, for example,internal to the server 125 and/or the mobile device 122, or at anexternal location.

The mobile device 122 is configured to execute routing algorithms todetermine an optimum route to travel along a road network from an originlocation to a destination location in a geographic region. Using inputfrom the end user, the navigation device 122 examines potential routesbetween the origin location and the destination location to determinethe optimum route. The navigation device 122 may then provide the enduser with information about the optimum route in the form of guidancethat identifies the maneuvers required to be taken by the end user totravel from the origin to the destination location. Some mobile device122 show detailed maps on displays outlining the route, the types ofmaneuvers to be taken at various locations along the route, locations ofcertain types of features, and so on.

The mobile device 122 is also configured to execute the update script orother type of navigation patch on local map data. The navigation device122 receives the update script from the server 125 by way of network127. The update script includes less data than a wholesale replacementof a portion of the database or BLOB and requires less bandwidth and/ortransmission time than the portion of the database or BLOB. The updatescript may be stored in a computer readable medium coupled to the server125 or the navigation device 122.

FIG. 13 illustrates an exemplary mobile device 122 of the system ofFIG. 1. The mobile device 122 includes a processor 200, a memory 204, aninput device 203, a communication interface 205, position circuitry 207,and a display 211. Additional, different, or fewer components arepossible for the mobile device/personal computer 122.

At act S201, the communication interface 205 or processor 200 mayreceive an update script or navigational patch file from the server 125.The patch file may be received based on a request sent by thecommunication interface 205 through the network 127 based oninstructions from the user input 203. The patch file may be receivedbased on a schedule. For example, updates may be sent weekly, monthly,or quarterly. In one example, the schedule is defined by the mobiledevice 122. In another example, the schedule is defined according to asubscription or an online purchase.

At act S203, the processor 200 determines a first series of bits for anobject of a BLOB for a current version of navigation data thatcorresponds to the navigation patch file. In one example, the navigationpatch file lists an object identifier (e.g., name or number) that isreferenced in the current version of the navigation data. In anotherexample, the processor 200 unpacks the navigation patch file to identifythe payload data. The payload data is matched to the objects of thecurrent version of the navigation data.

At act S205, the processor 200 duplicates the first series of bits by apredetermined number of times to form a bit string. For example, theprocessor 200 identifies a first bit in the bit stream and duplicatesthe bit to a byte length string of data. The processor 200 may repeatthis technique for each bit in the first series of bits. In one example,vector multiplication is used to convert the bit to a byte lengthstring. The vector multiplication may be a multiplier vector [1 1 1 1 11 1 1] multiplied by the bit. Thus,[1 1 1 1 1 1 1 1]*1 is [1 1 1 1 1 1 11 ], and [1 1 1 1 1 1 1 1 ]*0 is [0 0 0 0 0 0 0 0].

At act S207, the processor 200 updates the bit string according to thenavigation patch file. In one example, the navigation patch fileincludes bytes that are inserted into a particular location in the bitstring. In one example, the navigation patch file includes bytes thatare appended to the end of the bit string. In one alternative, thenavigation path file includes locations whether the values in the bitstring should be flipped.

At act S209, the processor 200 reduces the updated bit string accordingto the predetermined number of times to form a second series of bits. Inother words, the byte length series of bits [1 1 1 1 1 1 1 1] and [0 0 00 0 0 0 0] are reduced to 1 and 0, respectively. The reduction may beimplemented using a dot product of [1 0 0 0 0 0 0 0] and the series ofbits. Thus, the dot product of [1 1 1 1 1 1 1 1] and [1 0 0 0 0 0 0 0]is 1, and the dot product of [0 0 0 0 0 0 0 0] and [1 0 0 0 0 0 0 0]iso.

At act S211, the processor 200 inserts the second series of bits inplace of the first series of bits in the object of the BLOB. Thereplacement step of act S211 may repeated for multiple objects describedin the navigational patch file. The processor 200 may test thenavigational database after the bits are inserted. The test may be anintegrity check, a parity check, or a routing algorithm that is appliedto the updated navigational data. When the test is successful, theupdate is made permanent and an acknowledgement is presented by thedisplay 211. When the test is unsuccessful, the update may be reversedan error message may be presented on display 211.

The processor 200 executes the navigational patch file on a set ofnavigation data stored in memory 204. The set of navigation data may bean entire geographic database. The set of navigation data may be asubset of the geographic database. For example, the subset may be cachedaccording to the geographic position of the mobile device 122. Forexample, the position circuitry 207 may determine the geographicposition (e.g., latitude and longitude) and request the set ofnavigation data from the server 125 accordingly. In another example, theuser may select a geographic region to be loaded in the memory 204through the user input 203.

The positioning circuitry 207 may include a Global Positioning System(GPS), Global Navigation Satellite System (GLONASS), or a cellular orsimilar position sensor for providing location data. The positioningsystem may utilize GPS-type technology, a dead reckoning-type system,cellular location, or combinations of these or other systems. Thepositioning circuitry 207 may include suitable sensing devices thatmeasure the traveling distance, speed, direction, and so on, of themobile device 122. The positioning system may also include a receiverand correlation chip to obtain a GPS signal. Alternatively oradditionally, the one or more detectors or sensors may include anaccelerometer built or embedded into or within the interior of themobile device 122. The accelerometer is operable to detect, recognize,or measure the rate of change of translational and/or rotationalmovement of the mobile device 122. The mobile device 122 receiveslocation data from the positioning system. The location data indicatesthe location of the mobile device 122.

The input device 203 may be one or more buttons, keypad, keyboard,mouse, stylist pen, trackball, rocker switch, touch pad, voicerecognition circuit, or other device or component for inputting data tothe mobile device 100. The input device 203 and the display 211 may becombined as a touch screen, which may be capacitive or resistive. Thedisplay 211 may be a liquid crystal display (LCD) panel, light emittingdiode (LED) screen, thin film transistor screen, or another type ofdisplay.

The controller 200 and/or processor 300 may include a general processor,digital signal processor, an application specific integrated circuit(ASIC), field programmable gate array (FPGA), analog circuit, digitalcircuit, combinations thereof, or other now known or later developedprocessor. The controller 200 and/or processor 300 may be a singledevice or combinations of devices, such as associated with a network,distributed processing, or cloud computing.

The memory 204 and/or memory 301 may be a volatile memory or anon-volatile memory. The memory 204 and/or memory 301 may include one ormore of a read only memory (ROM), random access memory (RAM), a flashmemory, an electronic erasable program read only memory (EEPROM), orother type of memory. The memory 204 and/or memory 301 may be removablefrom the mobile device 122, such as a secure digital (SD) memory card.

The communication interface 205 and/or communication interface 305 mayinclude any operable connection. An operable connection may be one inwhich signals, physical communications, and/or logical communicationsmay be sent and/or received. An operable connection may include aphysical interface, an electrical interface, and/or a data interface.The communication interface 205 and/or communication interface 305provides for wireless and/or wired communications in any now known orlater developed format.

The network 127 may include wired networks, wireless networks, orcombinations thereof. The wireless network may be a cellular telephonenetwork, an 802.11, 802.1, 802.20, or WiMax network. Further, thenetwork 127 may be a public network, such as the Internet, a privatenetwork, such as an intranet, or combinations thereof, and may utilize avariety of networking protocols now available or later developedincluding, but not limited to TCP/IP based networking protocols.

The term “computer-readable medium” includes a single medium or multiplemedia, such as a centralized or distributed database, and/or associatedcaches and servers that store one or more sets of instructions. The term“computer-readable medium” shall also include any medium that is capableof storing, encoding or carrying a set of instructions for execution bya processor or that cause a computer system to perform any one or moreof the methods or operations disclosed herein.

In a particular non-limiting, exemplary embodiment, thecomputer-readable medium can include a solid-state memory such as amemory card or other package that houses one or more non-volatileread-only memories. Further, the computer-readable medium can be arandom access memory or other volatile re-writable memory. Additionally,the computer-readable medium can include a magneto-optical or opticalmedium, such as a disk or tapes or other storage device to capturecarrier wave signals such as a signal communicated over a transmissionmedium. A digital file attachment to an e-mail or other self-containedinformation archive or set of archives may be considered a distributionmedium that is a tangible storage medium. Accordingly, the disclosure isconsidered to include any one or more of a computer-readable medium or adistribution medium and other equivalents and successor media, in whichdata or instructions may be stored. These examples may be collectivelyreferred to as a non-transitory computer readable medium.

In an alternative embodiment, dedicated hardware implementations, suchas application specific integrated circuits, programmable logic arraysand other hardware devices, can be constructed to implement one or moreof the methods described herein. Applications that may include theapparatus and systems of various embodiments can broadly include avariety of electronic and computer systems. One or more embodimentsdescribed herein may implement functions using two or more specificinterconnected hardware modules or devices with related control and datasignals that can be communicated between and through the modules, or asportions of an application-specific integrated circuit. Accordingly, thepresent system encompasses software, firmware, and hardwareimplementations.

In accordance with various embodiments of the present disclosure, themethods described herein may be implemented by software programsexecutable by a computer system. Further, in an exemplary, non-limitedembodiment, implementations can include distributed processing,component/object distributed processing, and parallel processing.Alternatively, virtual computer system processing can be constructed toimplement one or more of the methods or functionality as describedherein.

Although the present specification describes components and functionsthat may be implemented in particular embodiments with reference toparticular standards and protocols, the invention is not limited to suchstandards and protocols. For example, standards for Internet and otherpacket switched network transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP,HTTPS) represent examples of the state of the art. Such standards areperiodically superseded by faster or more efficient equivalents havingessentially the same functions. Accordingly, replacement standards andprotocols having the same or similar functions as those disclosed hereinare considered equivalents thereof.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, and it can bedeployed in any form, including as a standalone program or as a module,component, subroutine, or other unit suitable for use in a computingenvironment. A computer program does not necessarily correspond to afile in a file system. A program can be stored in a portion of a filethat holds other programs or data (e.g., one or more scripts stored in amarkup language document), in a single file dedicated to the program inquestion, or in multiple coordinated files (e.g., files that store oneor more modules, sub programs, or portions of code). A computer programcan be deployed to be executed on one computer or on multiple computersthat are located at one site or distributed across multiple sites andinterconnected by a communication network.

The processes and logic flows described in this specification can beperformed by one or more programmable processors executing one or morecomputer programs to perform functions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application specific integrated circuit).

As used in this application, the term ‘circuitry’ or ‘circuit’ refers toall of the following: (a)hardware-only circuit implementations (such asimplementations in only analog and/or digital circuitry) and (b) tocombinations of circuits and software (and/or firmware), such as (asapplicable): (i) to a combination of processor(s) or (ii) to portions ofprocessor(s)/software (including digital signal processor(s)), software,and memory(ies) that work together to cause an apparatus, such as amobile phone or server, to perform various functions) and (c) tocircuits, such as a microprocessor(s) or a portion of amicroprocessor(s), that require software or firmware for operation, evenif the software or firmware is not physically present.

This definition of ‘circuitry’ applies to all uses of this term in thisapplication, including in any claims. As a further example, as used inthis application, the term “circuitry” would also cover animplementation of merely a processor (or multiple processors) or portionof a processor and its (or their) accompanying software and/or firmware.The term “circuitry” would also cover, for example and if applicable tothe particular claim element, a baseband integrated circuit orapplications processor integrated circuit for a mobile phone or asimilar integrated circuit in server, a cellular network device, orother network device.

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andanyone or more processors of any kind of digital computer. Generally, aprocessor receives instructions and data from a read only memory or arandom access memory or both. The essential elements of a computer are aprocessor for performing instructions and one or more memory devices forstoring instructions and data. Generally, a computer also includes, oris operatively coupled to receive data from or transfer data to, orboth, one or more mass storage devices for storing data, e.g., magnetic,magneto optical disks, or optical disks. However, a computer need nothave such devices. Moreover, a computer can be embedded in anotherdevice, e.g., a mobile telephone, a personal digital assistant (PDA), amobile audio player, a Global Positioning System (GPS) receiver, to namejust a few. Computer readable media suitable for storing computerprogram instructions and data include all forms of non-volatile memory,media and memory devices, including by way of example semiconductormemory devices, e.g., EPROM, EEPROM, and flash memory devices; magneticdisks, e.g., internal hard disks or removable disks; magneto opticaldisks; and CD ROM and DVD-ROM disks. The processor and the memory can besupplemented by, or incorporated in, special purpose logic circuitry.

To provide for interaction with a user, embodiments of the subjectmatter described in this specification can be implemented on a devicehaving a display, e.g., a CRT (cathode ray tube) or LCD (liquid crystaldisplay) monitor, for displaying information to the user and a keyboardand a pointing device, e.g., a mouse or a trackball, by which the usercan provide input to the computer. Other kinds of devices can be used toprovide for interaction with a user as well; for example, feedbackprovided to the user can be any form of sensory feedback, e.g., visualfeedback, auditory feedback, or tactile feedback; and input from theuser can be received in any form, including acoustic, speech, or tactileinput.

Embodiments of the subject matter described in this specification can beimplemented in a computing system that includes a back end component,e.g., as a data server, or that includes a middleware component, e.g.,an application server, or that includes a front end component, e.g., aclient computer having a graphical user interface or a Web browserthrough which a user can interact with an implementation of the subjectmatter described in this specification, or any combination of one ormore such back end, middleware, or front end components. The componentsof the system can be interconnected by any form or medium of digitaldata communication, e.g., a communication network. Examples ofcommunication networks include a local area network (“LAN”) and a widearea network (“WAN”), e.g., the Internet.

The computing system can include clients and servers. A client andserver are generally remote from each other and typically interactthrough a communication network. The relationship of client and serverarises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other.

The illustrations of the embodiments described herein are intended toprovide a general understanding of the structure of the variousembodiments. The illustrations are not intended to serve as a completedescription of all of the elements and features of apparatus and systemsthat utilize the structures or methods described herein. Many otherembodiments may be apparent to those of skill in the art upon reviewingthe disclosure. Other embodiments may be utilized and derived from thedisclosure, such that structural and logical substitutions and changesmay be made without departing from the scope of the disclosure.Additionally, the illustrations are merely representational and may notbe drawn to scale. Certain proportions within the illustrations may beexaggerated, while other proportions may be minimized. Accordingly, thedisclosure and the figures are to be regarded as illustrative ratherthan restrictive.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of the invention or of what may beclaimed, but rather as descriptions of features specific to particularembodiments of the invention. Certain features that are described inthis specification in the context of separate embodiments can also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable sub-combination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a sub-combination or variation of a sub-combination.

Similarly, while operations are depicted in the drawings and describedherein in a particular order, this should not be understood as requiringthat such operations be performed in the particular order shown or insequential order, or that all illustrated operations be performed, toachieve desirable results. In certain circumstances, multitasking andparallel processing may be advantageous. Moreover, the separation ofvarious system components in the embodiments described above should notbe understood as requiring such separation in all embodiments, and itshould be understood that the described program components and systemscan generally be integrated together in a single software product orpackaged into multiple software products.

One or more embodiments of the disclosure may be referred to herein,individually and/or collectively, by the term “invention” merely forconvenience and without intending to voluntarily limit the scope of thisapplication to any particular invention or inventive concept. Moreover,although specific embodiments have been illustrated and describedherein, it should be appreciated that any subsequent arrangementdesigned to achieve the same or similar purpose may be substituted forthe specific embodiments shown. This disclosure is intended to cover anyand all subsequent adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the description.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b) and is submitted with the understanding that it will not beused to interpret or limit the scope or meaning of the claims. Inaddition, in the foregoing Detailed Description, various features may begrouped together or described in a single embodiment for the purpose ofstreamlining the disclosure. This disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter may be directed toless than all of the features of any of the disclosed embodiments. Thus,the following claims are incorporated into the Detailed Description,with each claim standing on its own as defining separately claimedsubject matter.

It is intended that the foregoing detailed description be regarded asillustrative rather than limiting and that it is understood that thefollowing claims including all equivalents are intended to define thescope of the invention. The claims should not be read as limited to thedescribed order or elements unless stated to that effect. Therefore, allembodiments that come within the scope and spirit of the followingclaims and equivalents thereto are claimed as the invention.

I claim:
 1. A method comprising: identifying, using a processor, aseries of bits representative of a first binary large object (BLOB) fornavigation data including road segments and road attributes;duplicating, using the processor, each bit of the series of bits apredetermined number of times to form a first bit string, wherein thefirst bit string is larger than the series of bits by a factor of thepredetermined number; performing a binary difference of the first bitstring to a second bit string representative of a second BLOB; andstoring a result of the binary difference in a navigation patch file. 2.The method of claim 1, wherein the predetermined number is
 8. 3. Themethod of claim 1, wherein a 1, bit in the series of bits corresponds to11111111 in the first bit string and a 0 bit in the series of bitscorresponds to 00000000 in the first bit string.
 4. The method of claim1, further comprising: identifying, using the processor, a second seriesof bits representative of the second BLOB for navigation data includeroad segments and road attributes; and duplicating, using the processor,each bit of the second series of bits by the predetermined number oftimes to form the second bit string, wherein the second bit string islarger than the second series of bits by a factor of the predeterminednumber.
 5. The method of claim 1, wherein the binary difference compareseach bit of the first bit string to a corresponding bit of the secondbit string.
 6. The method of claim 1, wherein the binary differencecompares a hexadecimal representation of the first bit string to ahexadecimal representation of the second bit string.
 7. The method ofclaim 1, further comprising: applying the navigation patch file to athird BLOB of a navigation database.
 8. The method of claim 7, whereinapplying the navigation patch file comprises: duplicating each bit ofthe third BLOB series in a format of the navigation database by thepredetermined number of times to form a third bit string; modifying thethird bit string based on the navigation patch file; and removing bitsof the third bit string to return to the format of the navigationdatabase.
 9. The method of claim 1, further comprising: identifying anonstandard number of bits in the first BLOB, wherein the duplicatingeach bit of the series of bits is in response to the nonstandard numberof bits.
 10. The method of claim 1, wherein the BLOB is part of acomplete navigation file.
 11. An apparatus comprising: at least oneprocessor; and at least one memory including computer program code forone or more programs; the at least one memory and the computer programcode configured to, with the at least one processor, cause the apparatusto at least perform: determine a first series of bits represents anobject of a binary large object (BLOB) for existing navigation datainclude road segments and road attributes; identify a second series ofbits for a new version of the object of the BLOB; inflating the firstseries of bits by a predetermined number of times to form a first bitstring, wherein the first bit string is larger than the first series ofbits by a factor of the predetermined number; inflating the secondseries of bits by the predetermined number of times to form a second bitstring, wherein the second bit string is larger than the second seriesof bits by a factor of the predetermined number; calculating a binarydifference of the second bit string and the first bit string; andstoring location values for a result of the binary difference in anavigation patch file.
 12. The apparatus of claim 11, wherein thelocation values indicate byte sequence numbers in which a difference wascalculated between the second bit string and the first bit string. 13.The apparatus of claim 11, wherein the predetermined number is a basenumber indicative of a standard character value.
 14. The apparatus ofclaim 13, wherein the base number is 8 or
 16. 15. The apparatus of claim11, wherein the at least one memory and the computer program codeconfigured to, with the at least one processor, cause the apparatus toat least perform: calculate a modulus function based on thepredetermined number for the BLOB; and define the object when a resultof the modulus function is nonzero.
 16. The apparatus of claim 11,wherein the at least one memory and the computer program code configuredto, with the at least one processor, cause the apparatus to at leastperform: send the navigation patch file based on a time schedule or arequest corresponding to a navigation device.
 17. The apparatus of claim11, wherein the object includes a nonstandard number of bits that is notdivisible by
 8. 18. A non-transitory computer readable medium includinginstructions that when executed are operable to: receive a navigationpatch file; determine a first series of bits for an object of a binarylarge object (BLOB) for a current version of navigation data thatcorresponds to the navigation patch file; duplicate the first series ofbits by a predetermined number of times to form a bit string; update thebit string according to the navigation patch file; reduce the updatedbit string according to the predetermined number of times to form asecond series of bits; and insert the second series of bits in place ofthe first series of bits in the object of the BLOB.
 19. Thenon-transitory computer readable medium of claim 18, wherein thenavigation data includes road segment attributes.
 20. The non-transitorycomputer readable medium of claim 18, wherein the object includes anumber of bits that is not divisible by 8.